


Their not-so secret trysts

by amamiya_toki



Category: Cardfight!! Vanguard
Genre: Aphrodisiacs, Barebacking, M/M, Masturbation, Originally Posted on Tumblr, Past Child Abuse, Personality Swap
Language: English
Status: Completed
Published: 2017-08-14
Updated: 2017-08-14
Packaged: 2018-12-10 04:31:35
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 5,037
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11684124
Author URL: https://archiveofourown.org/users/amamiya_toki/pseuds/amamiya_toki
Summary: Kai returns home to an unpleasant surprise, but he can't say that he hates it. That doesn't mean that he likes it either. Dealing with his lover's alternate identity is difficult, especially when things get out of his control.Originally posted on tumblr on 8th November 2014





	Their not-so secret trysts

**Author's Note:**

> This was done under the influence of a cold and stress, so it lacks a lot of the "holding back" that I do when doing smut (like the terms I use, the language, the images I'm trying to convey) which here is almost non-existent.
> 
> This is set in an alternate universe, where Kai and Aichi meet but under a very different circumstance and that no one plays Vanguard. Aichi has dissociative identity disorder, formerly known as Multiple Personality Disorder. Both of Aichi's personalities are in love with Kai.
> 
> In this story, Aichi's alternate personality (which is Psy-Aichi, actually) is called "Ayuchi", or just "Ayu" as Kai calls him. "Ayuchi" is the old Japanese form of "Aichi". Aichi is vaguely aware of Ayuchi's existence but does not know of his existence.
> 
> To note, edible aphrodisiacs aren't good for the body. Someone already pointed it out. I didn't consider that when I was writing this.

It was half past midnight when Kai returned home, having had a drinking session with a client earlier that evening.

He actually had intended to return earlier today, but typical of company politics and with his position he could not refuse his boss's demands, as he was the only person who was deemed capable enough for the task. As much as he appreciated that he was being recognized for his abilities, he wished that his superiors would not push all the work to him. At the very least, give his colleagues a chance to shine, too. Then again, he had been planning to work his way up the corporate ladder, just as his late father did in his youth.

Well, the good news is that he was granted a day off, so he need not return to work until Monday. Including the weekend, that was three precious days to spend with the person he loves.

After removing his shoes and placing them in the shoe cabinet, he removed his coat before heading into the combined living-dining area. There, he placed his briefcase on the sofa, leaning it against one of its armrests. He removed his suit jacket, loosened his tie and undid the first two buttons of his shirt.

He grabbed a much-needed drink of water from the kitchen before heading to the bedroom.

Opening the door of the room, he took a peek inside. As expected, he found the person he was looking for tucked snugly under the covers, fast asleep.

He entered the room quietly, making as little noise as possible. He retrieved a set of clean clothes—a plain cotton T-shirt, a pair of sweatpants and boxers from the closet, with the intention of taking a shower before he turned in for the night.

Before leaving the room, he crept over to where his beloved lay asleep, so that he could place a kiss on that soft, supple cheek. However, something surprising and terribly unexpected happened. As he pulled away, an arm shot out, grabbing his tie and pulling him downwards. His lips met with another pair that was warm, luscious and familiar, yet at the same time cold and foreign.

As if to keep him from being distracted, the other person forced his tongue into his slightly-parted lips. Kai was most definitely dumbfounded; getting french-ed after returning home from a long day at work was not something that happened every day, nor had it ever happened before. He should kiss back, but he had been too surprised to actually respond for several seconds. When he finally got a grasp of what was going on, he placed his hands on the other person's shoulders to pry him off his person.

"What do you think, you're doing…" Kai growled, his brows furrowing into a frown. "Ayu?"

Hearing Kai spit his name out in a hiss, he gave a light chuckle, resisting Kai's attempts to push him away. He wound his arms that had been wrapped around Kai's upper torso even tighter, clinging onto him.

"You don't have to sound so unhappy to see me, Kai. I haven't been out for such a long, long time. Aren't you happy to see me?"

"Not really."

"Such a cold reaction. You never show that to Aichi, do you? But that's what I love about you. This freezing glance as you glare at me, the way your lips curve into a frown, and that deliciously sexy voice that drips with malice. I love it, I love all of it."

Ayu… or Ayuchi as he calls himself, raised his hand to stroke Kai's cheek, but it was swiftly slapped away before he could even place his fingertips on the smooth skin.

"What happened to Aichi?"

"He's asleep, of course. In here." the blue-haired youth placed his hand over his chest, over his heart. "It was getting so stuffy in there, I must say, watching the two of you go at it. It was so sweet and fluffy that I could puke.

"Say, Kai, do you know something?" Ayuchi continued. "You should have seen how pitiful cute little Aichi was earlier. The poor dear had been looking forward to having dinner with you tonight since you promised to return home early tonight. You should have seen how his hopeful little face twists into one of despair, how he broke down into a little puddle of tears. He was just so, so worried. Worried that his beloved Toshiki-kun was never going to come home, that his dear husband was seeing something someone else, which his precious person was going to leave his side and not come back. He was just so, so scared, you know. It was nothing but pathetic, really. I don't know what you even see in a weak little thing like him. Say, why don't you choose me instead?"

"Let go of me. I want to take a shower."

"Aww, don't change the subject so quickly. Stay a little while longer."

"I told you to let go of me."

"Hmph, fine." Ayuchi finally relented, freeing Kai from his grasp and leaning back so as to fall onto the bed. "Make it quick. I'll be waiting."

"Why should I listen to you?"

"Because you do, even if you say you won't."

"…"

Without replying, at least verbally, Kai left the bedroom with his change of clothes. Stripping out of his clothes quickly, he jumped into the shower. Turning on the faucet he savoured the feeling of the water running down his head, hair and body. It felt like the water was washing off the grime and dirt of the day, along with the exhaustion and stress. However, in his mind, there was still one thing that remains stuck, and it revolved around Ayuchi.

It had been a long time since he first met Aichi. At that time Ayuchi had already existed, deep in the depths of Aichi's consciousness. That was about sixteen years ago. They met at an orphanage and had been roommates until they had to leave the institute upon completing high school.

Kai had been an orphan since he was nine, after losing his parents in an accident. None of his relatives was willing to take him in and he was sent to the orphanage instead. There he met Aichi, a boy a year younger than him who would be his roommate. At that time, Aichi had already been there for two years. He had first thought of Aichi as a demure and timid child, perhaps because he was often picked on by the other children because of his small size. It didn't take long for Aichi to get attached to Kai since he was the only one who would stand up for him and protect him when he was getting beaten up.

However, one thing Kai did not know was that in the body of this small boy held a secret that even he himself was not aware of.

Kai learnt about it the hard way.

It happened around four months after Kai had joined the orphanage. One day, after returning from school, he had found a man speaking to Nitta Shin, who runs the institution, in the lobby. From their conversation, he learnt that this man was Aichi's father, who had come to demand his son to be returned to him, though he didn't catch the rest of their conversation as he was shooed away by one of the caretakers.

At that time, he could only be envious of Aichi. For a child who lost both his parents, who could blame him for feeling that way?

However, when he returned to his room, he found Aichi sitting on his bed; his head hung low in a strange, awkward silence. Being a self-centered kid who could only think from his own perspective, Kai had failed to notice this. Instead, he tried to hide his jealousy with a cool demeanour and a casual comment as he sat beside the boy.

_"Hey, Aichi, I heard that your dad's here? That's great! You're so lucky, still having one of your parents still around. It looks like he wants to take you back, too. I bet you must be really happy right now—"_

As Kai was talking… shooting his mouth off rather, he had failed to notice the building tension next to him that started to flare up. It kept building up more and more until it exploded with an explosive yet silent bang.

Before he realized what was going on, Kai found himself pushed down onto the bed, with a pair of hands cupping and squeezing down tight around his neck. He glimpsed at his roommate, looking at him in the eye. That brief moment was all he needed to know that this boy was not the timid child that he had known.

That sense of fear was something Kai would never forget.

If one of the caretakers hadn't entered their room at that timely moment, he could have lost his life. After they had gotten both sides calmed down, Shin-san spoke to him about Aichi's secret, and his past.

Aichi lost his mother after his younger sister was born. His father was devastated at the loss of his wife and turned to alcohol to drown his sorrows. The problem got from bad to worse, to the point that he started to take out his frustration on his son. The problem continued on with no one noticing this; kids getting bruises from 'falls' was nothing special, or so everyone thought. However, it was when he ascended to elementary school that his teacher got suspicious and took action.

However, as a child, Aichi could not understand why his father, his parent, would physically abuse him. He started to blame himself and started to develop ways to ease the pain. He started to mentally distance himself from the abuse to a state of dissociation. That lead to the birth of Ayuchi, an alternate personality who was resistant to the abuse and pain and everything terrible Aichi had to go through. Aichi, however, does not know of Ayuchi, nor does he retain the memories of what happens when Ayuchi takes over. Ayuchi, however, knows every little thing that happens to Aichi.

Unlike the timid and cowardly Aichi, Ayuchi was confident and daring. In a sense, they were like two completely different people who had to share the same body.

However, Kai didn't like Ayuchi. As a matter of fact, he loathes him. He doesn't really know the reason why himself, but perhaps it was because he felt that it was odd to see Ayuchi with Aichi's face and to hear him speak with Aichi's voice. When Ayuchi takes charge, it is as if Aichi had completely disappeared from this world.

Perhaps Kai's hate of Ayuchi was because of the fact that he himself had grown attached to Aichi. He had always been fond of the blue-haired boy, and somewhere early in their long years of being together, it felt natural to have him by his side. However, with Ayuchi, this sense of comfort was completely disrupted. Ayuchi, knowing this well, often makes him unsettled on purpose.

However, somehow or another, he was the only person who Ayuchi would ever listen or yield to, which to the adults was a huge relief.

But that was all the past. Kai had left the institute after he had finished high school, and so did Aichi. They both managed to get scholarships for the same university, and while they were studying they worked part-time. Along with the salary from those jobs and Kai's large inheritance, they managed to afford this apartment. After graduating, Kai got himself a job in a corporate company, and Aichi worked full-time in a nearby cafe, where he worked part-time during his university days.

For the past few years, Ayuchi appeared every now and then, but under certain conditions. The only times when he would was when was drunk, which was rare since he had a strangely high tolerance for alcohol, and when he was extremely upset about something and it affected him very badly.

In this case, it would be the latter, Kai sighs to himself as he finishes drying his hair with his towel and begins to get dressed in his pyjamas.

He hangs his wet towel on the rack, brushes his teeth and prepares himself to return to the bedroom once more.

What he sees when he does return was doesn't surprise him as he had expected it to happen, no thanks to his own unpleasant past experience.

Ayuchi was lying in the middle of the king-sized bed over the covers, naked with his clothes literally tossed to a corner of the room. He had the pillows propped behind him to support his back as he sat with his legs splayed. His right hand was between his legs, the middle three fingers that were coated with lube were buried deep in his hole. It seemed that fingering himself made him hard; his member was standing proud and tall, like a flagpole.

Seeing that Kai had returned, Ayuchi turned to glance at him, with half-lidded eyes that shone in the darkness with a glimmer of lust.

"Hey there." he gave Kai a coy smile. "You took too long in the shower; I decided to get things ready first."

Kai ignored his comment as he closed the door. "It's the middle of winter. If you do that, Aichi will catch a cold."

"Hmm… even when you're about to have a magical night of fun with me, it's Aichi that you're thinking of, huh… it makes me want to monopolize all of you. Maybe I should just remain out here forever."

"Don't you dare."

That threat was simply dismissed with the shrug of shoulders.

"Now now, don't be so stiff about it. I was merely joking."

Ayuchi removed his fingers, sliding them out of himself as he crawled over to the edge of the edge of the bed, where Kai was now standing. Getting on his knees he wrapped his arms around Kai's neck once again, clinging onto him like a koala on a branch. He buried his nose into the crook of his neck, taking a deep sniff.

"The smell of soap and shampoo… how lovely. How long has it been since I got a chance to relish this sensation?" Ayuchi gave a satisfied sigh, moving his hands down to Kai's waist and laying his head on his chest. "I love you, Kai. I really, really do."

How many years has this been happening, Kai wondered. Since they were in college? High school? No, it was much earlier, during the early to mid-years of Aichi's puberty, when he had difficulty understanding the changes in his body. Being the closest person to him, Kai had to teach him how to… for the lack of a better term, jerk off. Aichi was too embarrassed to do it himself and relied on Kai to help him. During the times when Aichi was Ayuchi, things got a little hotter: Ayu always insists on 'helping' by doing Kai's, with either his hands or, as time went by, his mouth. It was during high school when they first had sex, and that was in an empty classroom. However, that first time for Kai was not what he had imagined to be… it had ended up being with Ayuchi, rather than Aichi.

In this respect, he feels that he had wronged Aichi, and to make up to him he confessed his feelings to Aichi and asked him out. While he had done this as a way to relieve his guilt, his feelings for Aichi were genuine. However, he cannot deny that there are times when he doubts his own conscience.

While he dedicates himself to Aichi, he cannot deny that he is attracted to Ayuchi as well, especially when he tempts him with the face and the voice that he adores so much…

But he knows.

Kai knows how, despite how he presents himself, Ayuchi is much weaker than Aichi himself.

For Aichi, he simply lacks the confidence and the courage to stand up for himself. But for Ayuchi, he is always putting up a strong front, acting as if nothing in the world could affect him. However, that is nothing but a cover to hide his real self.

If Kai had to compare, he'd say that Ayuchi was like a child. When he wants something, he would use all means to get it. If he doesn't, he would throw a fit in protest. Not only that, but he is good in influencing others. But what makes him most like a child is that he is desperate for love and attention.

And that desperation… that desire to be loved was pure. However, he did not know what love really is. Because of this, his idea of love was twisted.

Kai knows all of that.

And because of that, he can't bring himself to truly hate Ayuchi, as much as he refuses to admit this.

Because… if he decides to accept Ayu, then what about Aichi?

Kai feels that if he accepts Ayuchi, it would be the same as denying Aichi's existence, or at the least, it would be the same as betraying him. He doesn't have it in him to do that.

What should he do?

What is the right thing to do?

He doesn't know, but…

"Hmm…?" Ayuchi gave a low hum, as Kai returned his embrace by putting his around his shoulders and holding him close and tight. "What happened? I thought you weren't in the mood tonight. What's with the sudden enthusiasm?"

"Be quiet," Kai instructed firmly.

Using his free hand, Kai cupped Ayu's chin and brought their lips together, melting into a slow kiss. This time there was no tongue involved, just the meshing of lips and a little sucking… the kind that the latter secretly loves. Sure it lacked the intensity of the previous kiss, but it was a lot more sensual. That, along with the feeling of Ayu's erection rubbing against him through his clothes, made Kai aroused.

Ayuchi seemed to have noticed Kai's growing bulge and smirked into the kiss.

When they parted, the first thing Ayu did was to grab Kai's T-shirt, with the intention of removing it. However, Kai stopped him.

"I can do it myself."

"You shouldn't have put them on in the first place." Ayuchi protested but was ignored, not that he minded since he had something to do.

As Kai removed his clothes, Ayuchi reached over to the bedside table to retrieve a few things: a half-used bottle of lube which he had used earlier and a small, strange-looking brown bottle with a white sticker label on it. These he placed on the bedside table.

However, that last object caught Kai's attention as he climbed on the bed to join Ayu.

"What's that?" he asked, staring at the bottle as he sat down.

"A 'love potion', or so it says here. It's a kind of aphrodisiac, and a strong one, too. I took one myself earlier while waiting for you, so I can vet for its effectiveness."

"Where… when did you get this?"

"Don't give me that accusing look; it wasn't me."

"Then how…"

"It was Aichi."

"You're lying."

"I'm not. It was a present from that queer red-headed friend of yours… Ren, was it? Aichi met him for tea last month and told that guy about his worries about his relationship with you. There was lots of talk about sex, or so I gathered, but I don't know the little details too well. Anyway, that Ren guy came over last week to drop these here. Aichi had been too shy to even think of using them, so he hid them where he thinks you can't find them. Since I thought that it would be a shame to waste something so wonderful, I decided to make use of it instead."

"Ahh. I see."

"But knowing you, you would refuse if I asked you to take it normally, so…" Ayu popped the bottle open, emptying the contents in his mouth before tossing the little plastic bottle onto the floor.

Before Kai could question his intentions, Ayuchi forced his lips on his again. Fortunately, he had caught Kai with his mouth open, allowing the liquid to be passed through the latter's mouth with little hassle. In order to prevent himself from choking Kai was forced to swallow it.

"How does it taste?"

"… Disgusting."

"I know, right? But this thing takes effect pretty quickly, so you'll be feeling its effects in no time. In the meantime…" Ayu positioned himself so that he was lying down, his chest pressing on Kai's thigh. "Let's have a little fun, shall we?"

He stretches his hands out, stroking Kai's hardening member with his long fingers. Kai flinched at the touch; compared to his own body temperature, Ayuchi's hands were much warmer… hot, even. Was this due to the effect of the aphrodisiac that Ayu had taken earlier?

Kai doesn't know, nor was he able to think about it. Having Ayu's fingers coiled around the base of his manhood and them moving up and down in a pumping motion, he was unable to stay focus on anything except that. And when the head was enveloped by a warm, wet cavern, he nearly lost all sense of reason.

"A…yu…!" Kai growled, trying to hold back the surge of sensations that erupted from his groin.

That damned little shit always knows how to target Kai at his weak points. He knows well enough how much Kai loves it when he was given head, and which are the spots and methods that make him shudder with pleasure; this he exploits and does it well.

Soon, Ayuchi removed his hands, using only his mouth to pleasure his loved one. He took little Toshiki into his mouth, as deep as he can manage without activating his gag reflex, which he had learnt how to suppress. Moving his head up, down and up again in a smooth-transitioning cycle, Ayuchi started to push Kai up towards the peak. When Kai began thrusting upwards to meet his movements, it was a sign that release was soon approaching.

However, Kai had no intention of being the only one.

Reaching his hand between Ayu's legs, he grabbed his erection and started pumping roughly. With Kai's still in his mouth, Ayuchi let out a cry; the former could feel the vibration of the sound with his member, and it felt good. Too good.

Kai clamped his other hand down on Ayuchi's head when the latter tried to take Kai out of his mouth, unable to hold back his moans and mewls from the rough treatment Kai had been administering to him. However, because Kai won't let go, they only came out as muffled sounds.

Ayuchi came first, his white essence spraying out onto both Kai's hand and the sheets. Kai soon followed, but not before freeing his grip on Ayu's head. He released his load over the blue-haired man's face, which had not been his intent.

"What a waste," Ayuchi sighed, wiping the cum off with his fingers and sticking them into his mouth. "Delicious."

Kai did the same, bringing his stained hand to his mouth and lapping it up. As always, it has the same taste as Aichi's.

But it looks like the aphrodisiac's finally taking effect, seeing how he is still hard even after coming. The same goes for Ayuchi, who is now snuggling up to him with his hands resting on his shoulders and his face nuzzled into his bare, muscular chest.

"Kaaaaaai," he mewed, rubbing his buttocks against Kai's erection like a horny kitten. "Hurry up and stick it in me already."

"Get me a condom first."

"Don't wanna." Ayu ran his finger along the side of Kai's jaw. "I want Kai to fill me up with his thick, hot milk. Lots and lots of it, until it overflows. Who knows, maybe if it's enough, I can finally bear Kai's child. Won't that be lovely?"

"It's not biologically possible; you know that."

"It won't hurt to dream." With a chuckle, Ayuchi got off Kai, positioning himself so that he was on all fours with his ass high up in the air facing Kai. Reaching his arms back, he used his fingers to spread his hole open to tempt Kai, eager and ready to be entered. "What are you waiting for? Take me. Fuck me rough, hard and deep… just like you always do."

Kai didn't need the invitation to do so. As Ayuchi was positioning himself, he was already reaching for the bottle of lube that was left on top of the bedside table. Dumping plenty of its contents in his hand, he quickly slicked himself up as he got on his knees.

Grabbing Ayu's hips, he entered him swiftly. Perhaps it was because he and Aichi did it the night before, or because Ayuchi was through in his preparations, Kai slid in easily. However, to a certain degree, it was still tight, but it was the snug kind of tightness that Kai liked the best.

Being entered quickly, Ayu let out a loud moan as he felt Kai's thick length fill him up. He was barely given any time to adjust to the intrusion before Kai started moving.

Heavy pants and high-pitched mewls, along with the smacking of skin on skin filled the room: the sounds of their lovemaking that echoed off the walls and filled their ears.

"Faster, Kai… go deeper… ahh, yes, that's it, right there…" Ayu begged and moaned, all between pants, grabbing the sheets in his balling fists. "Kai, hurry; make me come… send me over the edge…"

"I don't need you to tell me that." Kai groaned, digging his fingers deeper into the soft flesh of Ayuchi's hips, allowing himself to enter deeper into him.

When Ayu was no longer able to say anything but his name, trembling and panting with overwhelming pleasure, Kai knew that he had hit a critical spot. He aimed his following thrusts there, and with each time he enters a sharp but delectable sound hits his ears.

The ride towards their climax of passion was soon ending, with Ayuchi reaching it before Kai.

"K-Kai, I…" Ayu didn't get to finish speaking before he came for the second time, shooting his load onto the sheets.

With his release, he momentarily lost all strength in his body and would have collapsed onto the bed if Kai had not been holding onto him.

"Just because you came doesn't mean you can rest easy," Kai threatened through gritted teeth, still pounding hard and deep into his limping body. "Don't forget about me."

"Of course… I haven't…" Ayu tried to smirk, but only managed a grin. "Feel free to let it out inside… I'm all ready for you."

Kai didn't need his permission to do so, of course.

When he came, he buried himself fully inside Ayuchi, whose insides tightened as if to squeeze out every single drop of his essence.

"Even though you came earlier, you let out so much." Ayu teased, moving from his current position to get on his back after Kai had pulled out of him.

He spread his legs apart, giving Kai the full view of the white liquid that was dribbling out of him. Seeing this erotic sight, the latter moved instinctively. He pulled one of Ayuchi's legs over his shoulder and quickly entered him again, in a manner that was almost violent.

This time it felt even better; the heat of his hot cum still in Ayu's warm hole was strangely comfortable, and so was the unusual wetness of it. And judging by the expression he wore and the sweet sounds he was making, Kai could tell that Ayuchi was enjoying this new sensation as well.

As Kai continued to pound into him, Ayuchi started to have his right hand wrapped around his own erection, pumping it up and down in a matching rhythm to Kai's thrusts. The fingers of his left were toying with his nipples, abusing the little nub by pinching and rubbing it with his thumb and forefinger.

"Hoh?" Kai made a sound of amusement. "You still intend to masturbate while I'm fucking you?"

"It feels even better this way, don't you think? Plus… this sort of image isn't bad, is it?"

"It isn't. However," Kai grabbed Ayu's hands, lacing their fingers together and holding them above the latter's head. "I'd rather indulge of the image of you coming as I slam my blade into your sheath."

"Hmm… and as you blast all your love into me? That doesn't sound too bad."

"Be quiet and let me fuck you in peace for once."

"Make me."

Kai took up the challenge and of course, he won.

They two continued going at it for the next two hours or so until the aphrodisiac wore off. When that happened they were exhausted, sticky and sweaty amongst many other things, but the sex had been satisfying.

They took a quick shower and cleaned up the room before they drifted off to sleep with Ayu in Kai's arms.

When morning came, everything was back to normal, at least for Aichi, who did not suspect a thing. That was to be expected since he and Ayuchi did not share their memories. On his side, Kai hadn't breathed a word about it either.

It was like this every single time and would continue to be, as long as Ayuchi still emerges every now and then.

On Kai's side, he still feels confused and guilty about his relationship with Ayu. It would be very hard for him to speak of the matter to Aichi, but if he has to he would.

All he hopes is for Aichi to be able to accept this unknown side of him, and he knows he will. After all, no matter how different they are, the two of them are still one person—the one and only person who Kai loves dearly.

But until then, it looks like these not-so secret trysts will continue… at least on occasion.

**\- END -**


End file.
